Equipment used in air spray applications, such as spray foaming and spray coatings, typically require electricity for operation of various components such as heating elements, pumps and an air compressor. If the equipment is portable, electricity is provided by an engine driven generator. If portable, the components must be compact enough to transportation and are typically placed within the limited space of a trailer. For purposes of illustration, spray foam applications will be discussed but the application of the instant invention can be applied to spray coatings or wherein portable equipment is necessary for the generation of pressurized air, including oil fields. For illustration purposes the use of spray foam for insulating materials may be recognized. The use of spray foam can stop air and moisture infiltration, add strength to the building structure, provides an insulator that is permanent and will not sag, reduce the capacity requirements of HVAC, provide sound proofing, and so forth. Sprayed polyurethane foam has an aged R-value of approximately 6 per 1 inch thickness. Traditional fiberglass insulation is only stapled so it is difficult to fill cracks and uneven surfaces. Further, attachment of fiberglass insulation to metal surfaces is most impractical. Sprayed polyurea is an elastomer used in coatings of large surfaces such as tank liners, manhole and tunnel coatings, truck bed liners, and so forth.
Typically a foaming application includes an on-board power output generator for providing power to electrical consuming items. In this application the largest electrical consuming item is the compressor used for generating compressed air for creation of the foam product and application thereof. Onboard generators must be sufficiently large enough to simultaneously provide all the power needed to the foaming system, including the power to run the electric motor of the air compressor. Further, such electric motors have a high amp draw upon start-up wherein the generator must be sized to address the start-up amperage draw.
The application of the electric driven compressor typically requires an oversized generator to accommodate the start-up of the compressor motor. The generator must be sized to accommodate the start-up amps which may be 4-5 times the operating amp load. The larger generator adding cost and weigh. Piston compressors wear out quickly and need a tank. Rotary screw compressors run at a high speed and are noisier due to belt noise and more vibration. A disadvantage of these known motor driven systems is the need to provide a suitable coupling apparatus between the motor and the compressor to compensate for speed differential to maintain alignment and adjust for the proper rotational speed. Additionally, a known belt driven system requires a heavy base plate.
Another problem with the prior art is the sizing of an engine and generator motor, the start-up amps of the electric motor and ancillary items must be considered to prevent over taxing of the engine during startup. Finally, the amount of space consumed by a freestanding compressor must be addressed especially in those instances where portability is of concern.
WO2004/107534 discloses the combination of a pump and a compressor, powered by a single electric motor, by means of two freewheel bearings. More in detail, the motor is provided with a selector that reverses its rotation direction and the pump and the compressor are connected to the motor shaft respectively by a first and a second freewheel bearing, with an opposite engaging direction. Motion is then transmitted to the pump or the compressor by reversing motor rotation.
WO2005/101617 discloses a modified electric motor, providing it with two completely independent shafts, each connected to the rotor by means of a freewheel bearing. The shafts are protruding from opposite sides of the motor, which is thus located centrally between the two operating machines; the latter, as in the previous case, may be a pump and a compressor, or a pump and an aspirator.
The known prior art fails to disclose a generator compressor combination power system that provides an efficient system for producing electricity and compressed air. The generator compressor combination power system can be used for most any application. For instance, during construction a contractor needs access to electricity for operating of lights, electric driven power tools, heaters, air conditioners, electric pumps and so forth. Similarly, the need for compressed air for operation of pneumatic driven power tools, pneumatic pumps and so forth. Many such locations are temporary and so remote that electric land lines are impractical, such as certain oil field operations. Other installations need power systems to set up the land line systems. Yet another example is the use with any spray coating applications which are typically temporary in design. Still others need 100% back-up power systems. Previous known prior art power systems include the use of a belt driven piston type compressor operating at 800 to 1000 rpms or a belt driven rotary screw compressor operating at 4000 to 6000 rpms, all of which have to have engine generator combinations sized to handle the large startup amps of the compressor.